Abstract

Mitochondria are cytoplasmic organelles that participate in adenosine triphosphate (ATP) production through respiration and oxidative phosphorylation (OXPHOS), free radical formation and execution of apoptosis.
Perturbation of mitochondrial function has been proposed as one vital hallmark of cancer cells. Besides plenty of germline
and polymorphic sequence variations accumulated in both coding and noncoding regions of the mitochondrial genome (mitochondrial deoxyribonucleic acid (DNA); mtDNA), increased or reduced mtDNA copy number has also been increasingly described in a plethora of primary human
malignancies. Altered mtDNA quantity may act as an important player in the multistep carcinogenesis of at least some types
of human cancer by fuelling tumour initiation and/or advancement. In addition, mtDNA content turnover in bodily liquids from
cancer patients could be exploited as a novel molecular tool for early cancer screening and diagnosis.

Key Concepts:

Disruption of mitochondrial function and the oxidative phosphorylation system may lead to cancer occurrence and development.

MtDNA copy number changes have been frequently observed in a wide range of human malignancies.

Aberrant mtDNA quantity is correlated with many key clinicopathological features of cancer patients.

Alterations in mtDNA copy number have potential to affect cancer cell behaviours in vitro and in vivo.

mtDNA content alterations could be considered as a novel biomarker for early cancer detection and diagnosis.